© 2026 Nanjing Finechem Holdings Co., Ltd,
All Right Reserved
Chemical Name: L-Cysteine Hydrochloride Monohydrate
Chemical Formula: C3H7NO2S·HCl·H2O
Common Uses: Used in laboratories as a reagent, in food processing, and in pharmaceuticals for its antioxidant properties
Synonyms: L-2-Amino-3-mercaptopropionic acid hydrochloride monohydrate
Appearance: This material usually shows up as a white crystalline powder with a faint sulfur odor.
Hazard Class: Not classed as hazardous under GHS for most uses, but can cause problems if inhaled, ingested, or absorbed
Skin Contact: Might cause mild irritation
Eye Contact: Dust or powder contact will likely bring on redness, watering, and irritation
Inhalation: Inhaling dust from this powder could prompt coughing or discomfort in the airways
Ingestion: Gastrointestinal distress, like nausea or stomach upset, can show up if someone accidentally swallows a moderate amount
Chronic Effects: Not linked to long-term health issues at the exposure levels found in most laboratory or industrial settings
Main Component: L-Cysteine Hydrochloride Monohydrate
Purity: Typically more than 98 percent pure in analytical standards
Impurities: Levels of related amino acids and trace salts may be present but remain minimal in standard grades
CAS Number: 7048-04-6
EC Number: 200-157-7
Inhalation: Remove to fresh air and keep comfortable for breathing, rinse mouth if dust exposure felt
Skin Contact: Wash area with mild soap and water; seek medical attention for persistent redness or swelling
Eye Contact: Rinse eyes gently under running water for several minutes, lift upper and lower eyelid occasionally
Ingestion: Rinse mouth, drink small quantities of water, get checked by a medical professional if discomfort escalates
Symptoms: Watch for respiratory irritation, mild burning or itching of the skin or eyes
Suitable Extinguishers: Water spray, foam, dry chemical, and carbon dioxide all work in most situations
Special Hazards: Combustion can create sulfur oxides, carbon monoxide, and hydrochloric acid vapor
Precautions: Firefighters should use standard gear including self-contained breathing apparatus if heavy smoke or vapor appears
Advice: Stay upwind and avoid inhaling fumes; contain runoff to limit environmental exposure
Personal Protection: Use gloves and dust mask, prevent contact with eyes or exposed skin
Clean-Up: Sweep up powders carefully without raising dust, collect in labeled containers for disposal
Environmental Precautions: Prevent entry into watercourses or drains; avoid spreading by wind or water flow
Ventilation: Work in well-ventilated areas to keep airborne dust to a minimum
Handling: Move containers gently to avoid generating airborne dust. Wash hands after handling. Keep away from moisture sources and strong oxidizing agents.
Storage: Store in a tightly sealed container at room temperature. Keep container dry and out of direct sunlight. Isolate from incompatible chemicals like strong acids or oxidizers.
Incompatibility: Avoid storage with strong acids, alkalis, or oxidizing materials to prevent hazardous reactions or degradation.
Workplace Controls: Use local exhaust ventilation to reduce dust buildup. Maintain good general hygiene in lab or work settings. Employ routine surface cleaning to remove powder residues.
Personal Protection: Wear safety goggles or glasses with side shields, nitrile or latex gloves, and a standard lab coat. Use a dust mask or particulate respirator if working with powders in large amounts.
Exposure Limits: No official occupational exposure limits set for this specific substance in most jurisdictions, but keeping exposure as low as practical just makes sense.
Form: Solid powder
Color: White or almost white
Odor: Slight sulfur smell
Solubility: Readily dissolves in water
Melting Point: About 175°C (decomposes)
pH: Acidic solution in water, typically around pH 1 to 2 depending on solution strength
Stability: Keeps well in dry, sealed containers under regular conditions
Stability: Stable under normal use and storage settings
Hazardous Reactions: Can react with strong oxidizers or acids, producing toxic or corrosive gases
Avoid: Damp or humid spaces, open flames, and strong reagents
Decomposition: Heat or burning will generate sulfur oxides, carbon oxides, and hydrochloric acid fumes
Acute Toxicity: Low risk for toxicity in small, brief exposures
Eyes: Direct exposure brings on stinging and irritation
Skin: Prolonged or repeated contact can cause minor irritation
Inhalation: Powder inhalation usually results in coughing or throat discomfort
Ingestion: Larger amounts could lead to digestive upset, though serious poisoning is uncommon
Sensitization: No strong evidence of allergic sensitization through routine handling
Carcinogenicity: Not known to pose a risk in this area
Aquatic Toxicity: Considered low hazard at small concentrations; high levels may affect aquatic organisms
Persistence: Breaks down to natural amino acids and sulfur compounds in the environment
Bioaccumulation: Not likely to build up in animals or plants
Soil and Water Mobility: Water-soluble and likely to disperse rather than remain in sediment
Methods: Give preference to chemical waste collection systems for solvents and contaminated materials
Container Disposal: Triple rinse and offer containers for recycling or proper waste disposal
Do Not: Flush into surface or ground water, storm sewers, or uncontrolled municipal waste streams
UN Number: Typically not classified as dangerous goods for transport
Transport Hazards: Minimal, as this chemical isn’t flammable, explosive, or strongly toxic
Packing Requirements: Keep in sealed, labeled packaging to prevent leaks or spills
Best Practice: Handle with established safety procedures for powders, and minimize package damage in transit
Classification: Not listed on major hazardous substances lists from agencies like OSHA, IARC, or NTP
Reporting: Regular workplace chemical safety procedures apply. Maintain documentation of use and labeling in work environments.
Restrictions: General use in laboratories, food, and pharmaceuticals holds no special prohibitions under most national or regional laws
Employee Rights: Workers are entitled to know about the substances they handle and should receive proper training for safe use
